Inverter control method

Abstract

The invention discloses an inverter control method, which realizes efficient and stable control of an inverter through accurate voltage and current measurement, real-time power calculation, dynamic output adjustment, feedback monitoring and a protection mechanism so as to adapt to rapid change of a power grid and improve the adjustment capability of a power system, and realizes accurate control of the current and the voltage of the inverter through fine control of the current and the voltage of the inverter. The method realizes quick response to the change of the power grid, improves the working efficiency of the inverter and the stability of the power grid, is especially suitable for a distributed power supply with small distribution and storage capacity, and can meet the urgent demand of a power system for the quick adjustment capability.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to an inverter control method. Background Art

[0002] With the widespread use of renewable energy, inverters play an increasingly important role in power systems. Inverters not only facilitate the reverse flow of energy, but also provide quick support when electricity is needed.

[0003] However, existing inverter control methods have problems such as slow response speed and poor stability. In particular, it is difficult to achieve fast and accurate control when grid conditions change. Summary of the invention

[0004] The purpose of the present invention is to provide an inverter control method, which can achieve fine control of the current and voltage of the inverter through voltage and current inner loop control, power synchronization and compensation, improve the working efficiency of the inverter, and enhance its responsiveness in the power grid.

[0005] The purpose of the present invention can be achieved through the following technical solutions: an inverter control method, through accurate voltage and current measurement, real-time power calculation, dynamic output adjustment, feedback monitoring and protection mechanism, to achieve efficient and stable control of the inverter to adapt to the rapid changes of the power grid and improve the regulation ability of the power system, the method specifically includes the following steps: Step 1: Through accurate measurement of voltage and current and coordinate transformation, fine control of the current and voltage of the inverter is achieved; Step 2: Calculate instantaneous power in real time and synchronize it with the grid power, so that the inverter can quickly adapt to grid changes and achieve immediate response; Step 3: Use a real-time compensation mechanism to dynamically adjust the inverter output to meet the power system's urgent need for rapid regulation capabilities; Step 4: Add a feedback link to monitor the inverter output and adjust it according to the actual needs of the grid; Step 5: Add a protection link to automatically disconnect the inverter from the grid when a grid anomaly is detected.

[0006] Preferably, in step 1, voltage and current values ​​are detected by ADC or SDFM to provide real-time data support for the control algorithm.

[0007] Preferably, the coordinate transformation in step one includes Clark transformation and Park transformation.

[0008] Preferably, the power synchronization in step 2 is achieved by calculating the power factor and phase angle of the power grid, wherein the phase angle is detected by a phase-locked loop technology.

[0009] Preferably, the real-time compensation mechanism in step three includes adjusting the amplitude and phase of the inverter output current.

[0010] Preferably, the feedback link in step four includes voltage feedback and current feedback.

[0011] Preferably, the voltage feedback monitors the output voltage in real time through a voltage sensor and compares it with the expected voltage. After the voltage signal received by the controller is compared with the expected voltage, an error signal is generated according to the comparison result. The error signal is used to adjust the switching state of the power switch device so that the output voltage is consistent with the expected voltage. The output AC power supply voltage is first reduced to a lower level and then fed to the shutdown pin of the control IC. The control IC uses a fixed voltage from the inverter battery voltage to monitor the feedback signal. If the output voltage exceeds a predetermined value, the error amplifier is activated, thereby shutting down the inverter output PWM and reducing the output voltage to a safe level.

[0012] Preferably, the current feedback monitors the output current in real time through the current sensor, and feeds back the monitored current signal to the controller, which compares the received current signal with the expected current and adjusts the switching state of the switching device according to the comparison result, so that the output current is consistent with the expected current, and adopts a dual-loop control scheme of an inductor current inner loop with load current feedforward and an output voltage outer loop, wherein the outer loop is the output voltage instantaneous value feedback, and the inner loop is the inductor current instantaneous value feedback.

[0013] Preferably, the control method further includes a prediction step for predicting the future state of the power grid and responding in advance.

[0014] Preferably, the control method further includes a communication link for realizing information exchange and coordinated control between inverters.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) This control method can achieve efficient and stable control of the inverter through precise voltage and current measurement, real-time power calculation, dynamic output adjustment, feedback monitoring and protection mechanism. In particular, in step one, the voltage and current values ​​are detected by ADC or SDFM to provide real-time data support for the control algorithm, which helps to improve the inverter's response speed and control accuracy to grid changes. At the same time, in step two, the instantaneous power is calculated in real time and synchronized with the grid power, so that the inverter can quickly adapt to grid changes and achieve immediate response. This rapid response capability is crucial to maintaining the stable operation of the grid, especially when the grid fluctuates or the load suddenly changes, the output can be adjusted quickly to reduce the impact on the grid and improve the stability and reliability of the entire power system. (2) The control method adopts a real-time compensation mechanism to dynamically adjust the output of the inverter to meet the urgent need of the power system for rapid regulation capability. This dynamic adjustment capability enables the inverter to better adapt to the load changes of the power grid and optimize the regulation capability of the power system, thereby improving the flexibility and economy of the power system. (3) A feedback link is added to the control method to monitor the output of the inverter and adjust it according to the actual needs of the power grid. This not only improves the response speed of the system, but also enhances the safety and reliability of the system. A protection link is added to automatically disconnect the inverter from the power grid when a power grid abnormality is detected. This can effectively prevent power grid failures from causing damage to the inverter or other parts of the power grid. In addition, the preferred current feedback monitors the output current in real time through a current sensor and feeds the monitored current signal back to the controller. The controller compares the received current signal with the expected current and adjusts the switching state of the switching device according to the comparison result, so that the output current is consistent with the expected current. This closed-loop control strategy further enhances the safety and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0017] Figure 1 It is a flow chart of the overall implementation of the present invention. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1 As shown, an inverter control method realizes efficient and stable control of the inverter through accurate voltage and current measurement, real-time power calculation, dynamic output adjustment, feedback monitoring and protection mechanism to adapt to the rapid changes of the power grid and improve the regulation ability of the power system. The method specifically includes the following steps: Step 1: Through accurate measurement of voltage and current and coordinate transformation, fine control of the current and voltage of the inverter is achieved; Step 2: Calculate instantaneous power in real time and synchronize it with the grid power, so that the inverter can quickly adapt to grid changes and achieve immediate response; Step 3: Use a real-time compensation mechanism to dynamically adjust the inverter output to meet the power system's urgent need for rapid regulation capabilities; Step 4: Add a feedback link to monitor the inverter output and adjust it according to the actual needs of the grid; Step 5: Add a protection link to automatically disconnect the inverter from the grid when a grid anomaly is detected. Embodiment 1

[0020] In the context of residential solar systems, inverters convert the DC power generated by solar panels into AC power for home use or transmission to the grid by: Step 1: Use a high-precision analog-to-digital converter (ADC) to detect the voltage and current values ​​output by the solar panel in real time, and apply Clark transform and Park transform to convert the three-phase current and voltage signals into two-phase orthogonal signals in order to more accurately control the inverter; Step 2: Calculate the instantaneous power of the solar inverter in real time and synchronize it with the power of the grid. Power synchronization is achieved by calculating the power factor and phase angle of the grid, where the phase angle is detected by phase-locked loop technology. Step 3: Use a real-time compensation mechanism to adjust the inverter output current amplitude and phase according to grid demand, such as increasing output when grid load is peak and reducing output when grid load is low; Step 4: Add voltage feedback and current feedback links, monitor the output voltage and current through sensors, compare them with the expected values, and adjust the switching state of the inverter to keep consistent; Step 5: Add a protection link. Once a grid abnormality is detected, such as a voltage surge or frequency deviation, the inverter will be automatically disconnected from the grid to protect the system safety. Step 6: Predict the output of solar panels through historical data and weather forecasts, and adjust inverter settings in advance; Step 7: Realize information exchange and coordinated control among multiple inverters in the home to optimize energy management. Embodiment 2

[0021] In the context of industrial energy storage systems, inverters are used to manage the charging and discharging of battery energy storage systems to provide a stable power supply. The specific methods include: Step 1: Use a high-speed data acquisition system (SDFM) to detect the voltage and current values ​​between the battery energy storage system and the grid, and apply coordinate transformation techniques such as Clark transformation and Park transformation to achieve fine control of the inverter; Step 2: Calculate the instantaneous power of the energy storage inverter in real time and synchronize it with the grid power. Use the phase-locked loop technology to detect the phase angle of the grid to achieve accurate power synchronization. Step 3: Use a real-time compensation mechanism to adjust the inverter output current amplitude and phase according to grid demand, such as increasing output when grid load is peak and reducing output when grid load is low; Step 4: Add voltage feedback and current feedback links, monitor the output voltage and current through sensors, compare them with the expected values, and adjust the switching state of the inverter to keep consistent; Step 5: Add a protection link. Once a grid abnormality is detected, such as a voltage surge or frequency deviation, the inverter will be automatically disconnected from the grid to protect the system safety. Step 6: Use grid load forecasting and battery status forecasting to adjust the inverter’s charging and discharging strategy in advance; Step 7: Realize information exchange and coordinated control among multiple energy storage inverters in the industrial park to improve energy utilization efficiency.

[0022] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An inverter control method, characterized in that: Through accurate voltage and current measurement, real-time power calculation, dynamic output adjustment, feedback monitoring and protection mechanism, efficient and stable control of the inverter is achieved to adapt to the rapid changes of the power grid and improve the regulation ability of the power system. The method specifically includes the following steps: Step 1: Through accurate measurement of voltage and current and coordinate transformation, fine control of the current and voltage of the inverter is achieved; Step 2: Calculate instantaneous power in real time and synchronize it with the grid power, so that the inverter can quickly adapt to grid changes and achieve immediate response; Step 3: Use a real-time compensation mechanism to dynamically adjust the inverter output to meet the power system's urgent need for rapid regulation capabilities; Step 4: Add a feedback link to monitor the inverter output and adjust it according to the actual needs of the grid; Step 5: Add a protection link to automatically disconnect the inverter from the grid when a grid anomaly is detected.

2. The inverter control method according to claim 1, characterized in that: Step 1: Detect voltage and current values ​​through ADC or SDFM to provide real-time data support for the control algorithm.

3. The inverter control method according to claim 1, characterized in that: The coordinate transformation in step one includes Clark transformation and Park transformation.

4. The inverter control method according to claim 1, characterized in that: The power synchronization in step 2 is achieved by calculating the power factor and phase angle of the power grid, wherein the phase angle is detected by a phase-locked loop technology.

5. The inverter control method according to claim 1, characterized in that: The real-time compensation mechanism in step three includes adjusting the amplitude and phase of the inverter output current.

6. The inverter control method according to claim 1, characterized in that: The feedback link in step 4 includes voltage feedback and current feedback.

7. The inverter control method according to claim 6, characterized in that: Voltage feedback monitors the output voltage in real time through a voltage sensor and compares it with the desired voltage. After the voltage signal received by the controller is compared with the desired voltage, an error signal is generated according to the comparison result. The error signal is used to adjust the switching state of the power switching device to keep the output voltage consistent with the desired voltage. The output AC power supply voltage is first reduced to a lower level and then fed to the shutdown pin of the control IC. The control IC uses a fixed voltage from the inverter battery voltage to monitor the feedback signal. If the output voltage exceeds a predetermined value, the error amplifier is activated, thereby shutting down the inverter output PWM and reducing the output voltage to a safe level.

8. The inverter control method according to claim 6, characterized in that: Current feedback monitors the output current in real time through the current sensor, and feeds back the monitored current signal to the controller. The controller compares the received current signal with the expected current, and adjusts the switching state of the switching device according to the comparison result, so that the output current is consistent with the expected current. A dual-loop control scheme of an inductor current inner loop with load current feedforward and an output voltage outer loop is adopted, in which the outer loop is the instantaneous value feedback of the output voltage, and the inner loop is the instantaneous value feedback of the inductor current.

9. The inverter control method according to claim 1, characterized in that: The control method also includes a prediction phase to predict the future state of the power grid and respond in advance.

10. The inverter control method according to claim 1, characterized in that: The control method also includes a communication link for realizing information exchange and coordinated control between inverters.

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